2次函数y=f(x)满足f(1+根号3)=f(1-根号3)=0且最大值为3求f(x)
问题描述:
2次函数y=f(x)满足f(1+根号3)=f(1-根号3)=0且最大值为3求f(x)
答
设f(x)=ax^2+bx+c;
f(1+√3)=0;
f(1-√3)=0;
为零点,-b/a=2;c/a=-2;
(4ac-b^2)/4a=3;有最大值a得:a=-1;b=c=2;
f(X)=-x^2+2x+2